Direct reduction of iron from iron oxide pellets, lump ore, or other iron oxide containing feed material is usually performed in of a direct reduction furnace, such as a vertical shaft furnace. The feed material usually contains a significant proportion of finely divided material, or "fines", often created by abrasion of the pellets or lumps during handling. These fines are usually screened out prior to reduction. Direct reduction is carried out by contacting the feed material with hot reducing gases rich in carbon monoxide and hydrogen. The reducing gas is passed through a metal oxide containing burden in the furnace and withdrawn from the top of the furnace, along with metal oxide material in the form of finely divided particles, usually generated by abrasion in the furnace. The fines must then be separated from the gas. Heretofore all fines must have been disposed of, which has usually been done by placing the fines into stock piles or attempting to mix the fines with some binder to form a usable material.
The present invention treats these removed fines by reducing them and returning them to the direct reduction system as reduced metallized iron. This greatly enhances the economics of the direct reduction process, and dramatically reduces the amount of waste fines for disposal.